Abrasive articles



United States Patent ABRASIVE ARTICLES Donald G. Phillips, Hatboro, Pa., assignor to Precision Grinding Wheel Company, Incorporated, Philadelphia, Pa., a corporation of Maryland No Drawing. Filed Mar. 18, 1958, Ser. No. 722,625

Claims. (Cl. 51-298) This invention relates to abrasive articles and, more particularly, relates to grinding Wheels in which abrasive grains are held by an organic bond.

The primary object of this invention is to provide an active agent for an abrasive article which improves the quality of the bond and, hence, the quality of the abrasive article.

in accordance with this invention is has been found that the quality of an abrasive article employing an organic bond and particularly a grinding wheel employing such a bond can be materially improved by incorporating in the bond a metal silicon alloy preferably in a finely divided form. Exemplary of metal silicon alloys are alloys of silicon with iron, manganese, aluminum, chromium, nickel, vanadium, tungsten or zirconium. The metal silicon alloy will preferably contain from about 40% to about 80% silicon by weight. The preferred alloy is ferrosilicon.

The metal silicon alloy can, with excellent results, be incorporated in any conventional abrasive article, particularly grinding wheels, which have abrasive grains bonded together with an organic bond. For example, the abrasive article may contain abrasive grains such as, for example, grains of aluminum oxide or silicon carbide.

The organic bond for the abrasive grains may be any of the organic bonds well known for use in abrasive articles such as, for example, natural resins such as shellac, synthetic resins such as a melamine resin or a phenolic resin, e.g., phenolformaldehyde resin or phenolfurfural resin. natural rubber or synthetic rubber. The organic bond will preferably be from 50% to 95% by volume, advantageously 70% to 90% by volume, of the bond mass, that is of the mass of the organic bond plus ingredients admixed with the bond such as fillers and including the abrasive grains.

The metal silicon alloy will be from about 5% to about 50%, preferably to 30% by volume of the bond mass. The metal silicon alloy may be used without the addition of conventional fillers or any conventionally employed fillers such as, cryolite or lime, may be added if desired.

Abrasive articles in accordance with this invention, for example, grinding wheels, are readily made by procedures well known to the art. The bonding material in a finely divided dry form is admixed with the metal silicon filler and any other additives such as, additional fillers, and then added to the abrasive particles which have been previously wetted using a wetting agent such as a liquid phenoformaldehyde resin. The thus formed batch is then thoroughly mixed. It may then be cold pressed, preheated and pressed, or hot pressed to the desired shape in a conventional press. The formed articles are removed from the press and placed in an oven where the cure is efiected or completed.

The following specific examples, while not limiting, will further illustrate the invention.

Example I A portable grinding wheel having the following constituents is formed.

Percent by volume 30 grit aluminum oxide 48 Bond mass 43 Pore 9 the bond mass having the following make-up:

Percent by volume Phenolformaldehyde resin 54 Cryolite 20 Lime 3 Ferrosilicon alloy 23 Example II A grinding wheel having the following constituents is formed:

Percent by volume 60 grit silicon carbide 50 Bond mass ..f 27 Pore 23 the bond mass having the following make-up:

Percent by volume Analine-formaldehyde resin 62 Siliconmanganese alloy q 38 The dry bond mass is thoroughly mixed and then added to the abrasive particles which are previously wetted with a liquid furfural resin. This batch is thoroughly mixed and cold pressed to the desired shape of wheel. The wheel is then kept in an oven at 350 F. until cured.

What is claimed is:

1. An abrasive article consisting essentially of abrasive grains, an organic bonding uniting the grains as an integral body and a metal silicon alloy dispersed throughout the bond mass, the metal silicon alloy containing from about 40% to about silicon by weight and being from about 5% to about 50% by volume of the bond mass, the metal silicon alloy being an alloy of silicon with a member selected from the group consisting of iron, manganese, aluminum, chromium, nickel, vanadium, tungsten and zirconium, and the organic bond being a member selected from the group consisting of a phenolic resin, a melamine resin, an aniline resin and rubber.

2. A grinding wheel in accordance with claim 1 characterized in that the organic bond is a phenolformaldehyde resin.

3. A grinding wheel in accordance with claim 1 characterized in that the organic bond is an aniline formaldehyde resin.

4. A grinding wheel in accordance with claim 1 characterized in that the metal silicon alloy is a ferrosilicon alloy.

5. A grinding wheel in accordance with claim 1 characterized in that the organic bond is a phenol formaldehyde resin and the metal silicon alloy is a ferrosilicon alloy.

References Cited in the file of this patent UNITED STATES PATENTS 2,199,803 Light May 7, 1940 FOREIGN PATENTS 562,467 Great Britain July 3, 1944 

1. AN ABRASIVE ARTICLE CONSISTING ESSENTIALLY OF ABRASIVE GRAINS, AN ORGANIC BONDING UNITING THE GRAINS AS AN INTEGRAL BODY AND A METAL SILICON ALLOY DISPERSED THROUGHOUT THE BOND MASS, THE METAL SILICON ALLOY CONTAINING FROM ABOUT 40% TO ABOUT 80% SILICON BY WEIGHT AND BEING FROM ABOUT 5% TO ABOUT 50% BY VOLUME OF THE BOND MASS, THE METAL SILICON ALLOY BEING AN ALLOY OF SILICON WITH A MEMBER SELECTED FROM THE GROUP CONSISTING OF IRON, MANGANESE, ALUMINUM, CHROMIUM, NICKEL, VANADIUM, TUNGSTEN AND ZIRCONIUM, AND THE ORGANIC BOND BEING A MEMBER SELECTED FROM THE GROUP CONSISTING OF A PHENOLIC RESIN, A MELAMINE RESIN, AN ANILINE RESIN AND RUBBER. 